<div id="map"></div>

<script>
    var map = new mapboxgl.Map({
        container: 'map',
        style: 'mapbox://styles/mapbox/streets-v11',
        zoom: 0
    });

    var url = 'https://wanderdrone.appspot.com/';
    map.on('load', function() {
        var request = new XMLHttpRequest();
        window.setInterval(function() {
            // make a GET request to parse the GeoJSON at the url
            request.open('GET', url, true);
            request.onload = function() {
                if (this.status >= 200 && this.status < 400) {
                    // retrieve the JSON from the response
                    var json = JSON.parse(this.response);

                    // update the drone symbol's location on the map
                    map.getSource('drone').setData(json);

                    // fly the map to the drone's current location
                    map.flyTo({
                        center: json.geometry.coordinates,
                        speed: 0.5
                    });
                }
            };
            request.send();
        }, 2000);

        map.addSource('drone', { type: 'geojson', data: url });
        map.addLayer({
            'id': 'drone',
            'type': 'symbol',
            'source': 'drone',
            'layout': {
                'icon-image': 'rocket-15'
            }
        });
    });
</script>
